Not only Gdynia is worth shiplover's attention or interest in Poland.
However it is Gdynia that now offers maritime focused information for visitor or shiplover in English...
This website
http://www.legendamorska.pl/en.html provides info on Gdynia's maritime heritage and major attractions to see and visit...
The website lacks typical shipspotter information, but I am sure, if you are going to visit any of Polish ports, either me or other Polish members of Shipspotting will be ready to provide information on vantage points, etc. if you ask on this forum.